Insulating sheath for terminal post



P 1953 R. M. FISKE 2,636,065

INSULATING SHEATH FOR TERMINAL POST Filed July 1, 1950 IN V EN TOR.

Ransom M. F/ske BY 3 TI'ORNEY Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE INSULATING SHEATH FOR TERMINAL POST Ransom M; Fiske, San Diego, Calif., assignor to Consolidated Vultee AlrcraftCoI-poration, San

Diego, Calii'.','a corporation'ot Delaware 7 Application July-1, 1950,'SerialNo. 171,725

3 Claims. 1 I This invention relates: generally to insulators andmore particularly to an insulating cover. .or sheath for a terminal screw. An object of the present inventionis to provide an insulating member of a yieldable substance such as live rubber having anv improved formadapting it for ready and self-locking attachmentto a terminal screw. v

Another object of this invention is the provision of an improved insulating sheath fora terminal stud which iseasily installed and serves to isolate the terminal screw from dust, anddirt and to protect it from moisture.

Anotherobj ect' of this invention resides in providing an insulating cover for-a terminal screw consisting of a unitary molded body of yieldable material having such construction-that it canbe embracingly associated with the terminal. screw and which utilizes the resiliency of'thematerial of which it is formed to hold it uponthescrew. A further object of theinvention. is to produce an'efiicient and efiective insulating sheath for a terminal screw, which has asimple and economical construction and is particularly characterized by its ease of attachment and ability to remain in operative position. e

Other objects'and features of the inventionwill bereadily apparent to thoseskilled'in the art from the following specification and appended drawing illustrating a preferred embodiment of the invention in which: a

Figure 1 is a perspective view of a section of a cable terminal orpanel connector having associated therewith an insulating sheath or cover made in accordance with this invention. I Figure 2 isa sectional view inperspective of an insulating cover. 1 v

Figure 3 is a view in vertical section of the insulating cover of Figure 2 and illustrating the general appearanceof the cover when deformed under applied external pressure; and

Figure4 is a vertical sectional view of the insulating cover in mounted position on a terminal'post.

Having specific reference now to the drawing there is illustrateda usual cable terminal or electric panel connector, indicated generally by the numeral l; comprising a molded mounting'body member H formed of any suitable insulating material, such as the plastic Bakelite, or hard rubber, Body member ll comprises a base l2 having a centrally disposed, longitudinally extending raised portion iii. A plurality of pillars or columns l4 rise from base 12 andare arranged .in pairs on opposite sides of the raised portion l3, with those pillars [4 located on the same side of raised portion. l 3 being spaced equally onefrom the other.v .Theraised portion. l3, at the various locations intermediate succeeding columns 14, is pierced to. provide a plurality of, circular bores I5, eachof which terminates in a square-shaped recess [6. A plurality oi terminal posts I! are provided on the body member I. I. The terminal posts I! comprise screws l8 thethreaded shanks l9v of which are passedthroughbores IE to project their free ends Zllabove raised portion l3, andv have square-shaped headswhich fit into square-shaped recesses It to prevent the screws [8 from turn ing. Each of'the screws. I8 mountsa washer 2|, a lock washer 22, and a nut 23 to securethe screws l8 to thebody member H. Cables 2.4 are afiixed to the panel connector ID by fitting the cable tip or terminal 25. carried at the end of each cable Monte a terminal post I]. Each cable tip 25 has the metallicportion thereof which is clinched onto acable suitably encased in an insulating coverin 21, which covering may be made of any suitable plastic or other insulating material. After the desired number of electrical leads are fitted to a terminal post I1, they. are secured to the post by means of a washer 28, a lock washer 29, anda nut 30.

With the cable connections made, an insulating cover or sheath 3| may now be fitted to the terminal posts I l. The insulating cover or sheath 3!, in accordance with the invention, embodies a generally cup-shaped unitarybody memberhavingan annular end wall3 l and-arcuate side walls 35; in other words, sheath 3! in eiiect is a hollow cylinder having one endclosed. An integral tit or nob 36 is formed on and projectsfrom the exterior surface of end wall 34, and is positioned centrally thereon. Interiorly of the cup-shaped sheath3l there isprovided centrally in end wall 34 a recess'3'l which extends into tit 36 but not through it. The diameter of recess 3! is slightly less than the diameter of screw l 8 so that the end of screw IB- does not have free access to-recess 31. The tit 36 isshown in the drawingas'being generallya spherical-segment in shape. However the particular shape of the tit 36 does not form a part of this invention. What the invention does require is a protuberance of some kind on the exterior of end wall 34 and an interiorly located or blind recess. The purpose of this protuberance or tit 36 and the recess 31 will hereinafter be explained.

Sheath 3| is provided with a pair of oppositely disposeds1ots38and.39. Thesl0ts 38 and 39 extendlongitudinally fromthecpen end 4| of cup shaped portion 33 and terminate short of end wall 34.

Insulating cover or sheath 3| may be made of any readily deformable material which when dis torted under pressure tends to return to its original shape. Rubber is preferred as the resilient material to be used, including synthetic rubbers as well as natural rubber. Additionally, since the material from which insulating cover 3| is made is not a part of this invention, it is contemplated that any elastic deformable material having physical properties similar to rubber may be employed.

In use the insulating cover 3| is placed over a terminal screw IS with slots 38 and 39 positioned to fit over the ends of the cables 24 connected to i when force is applied to the tit 36 the upper end i i of sheath 3| will deform and the opening to the recess 37 will be enlarged. It is to be noted that the illustration of Figure 3 exaggerates the deformation that occurs, this is in order that the invention may be more readily understood. After enlargement of the opening to recess 31 continued application of the external force will readily fit the end of screw I8 into recess 31.

'The natural resiliency of the material comprising the sheath 3| will afford a circumferentially applied force which causes the sheath 3| to tightly grip the end of the screw l8 and lock the sheath 3| to the screw l8 so that it cannot readily be jarred loose therefrom. Tit 36 enables the external deforming force to be readily applied to sheath 3| and at a location where it will facilitate the insertion of the end of screw l3 into blind recess 31.

Sheath 3| constructed with a deformable wall surface, which lies transverse to the longitudinal axis of the hollow body portion, and having a blind recessin this wall surface arranged to lie in axial alignment with the terminal screw to be enclosed by the sheath provides a locking or vice for enclosing a terminal post, which is simple in form and very readily applied. An effective insulating seal or cover is afforded about the terminal screw and the cable ends connected thereto which lessens to a very considerable degree the danger of shorts inadvertently developing between terminal posts.

It is understood, of course, that the sheath 3| is removable from the terminal screw and is adapted to be reused. The resilient force which holds the sheath to the terminal screw will yield to an external withdrawing pull without tearing or otherwise injuring the sheath.

While a certain preferred embodiment of the invention has been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What I claim is:

1. An insulating member for enclosing an electrical terminal screw to which cable ends are connectedcomprising a unitary hollow body of resilient deformable material within which the terminal screw and the cable ends connected thereto may be disposed, said hollow body having side walls provided with oppositely disposed slots adapted to be fitted about the cable ends connected to said terminal screw, and means for resiliently securing the insulating member to the free end of said terminal screw, said means comprisinga wall surface of said unitary hollow body, transverse to the longitudinal axis of the hollow body, and a protuberance on the exterior of said wall surface, said wall surface having a recess provided therein on the side thereof opposite to thatside having said protuberance, which recess extends within said protuberance, said interiorly located recess arranged to lie in axial alignment with said terminal screw, when the hollow body is positioned about the terminal screw, and being of lesser diameter than the diameter of the terminal screw for closely receiving the free end of the terminal screw to apply a resilient force circumferentially to said free end, said recess increasing in size on application of external force to said protuberance to permit insertion of said free end of the terminal screw.

2. An insulating cover element for enclosing an electrical terminal post to which cable ends are connected comprising a unitary body member of resilient deformable material, said body member having a hollow cylindrical portion comprising arcuate side walls, an end wall transverse to the longitudinal axis of said body member and being open at one end, said side walls provided with oppositely disposed, longitudinally extending, slots adapted to be fitted about the cable ends connected to said terminal post to encase said connected cable ends, and means for resiliently securing the insulating cover element to the'free end of said terminal post, said means comprising said end wall and a protuberance on the exterior surface of said end wall positioned centrally thereon, said end wall having a recess provided in the interior surface thereof, which recess extends into said protuberance, said recess arranged to lie in axial alignment with said terminal post when the body member is positioned about the terminal post, and being of lesser diameter than the diameter of the terminal post for closely receiving the free end of the terminal post to apply a resilient force circumferentially to said free end, said recess increasing in size on application of an external force to said protuberance to permit insertion of said free end of the terminal screw.

3. In a resilient, molded rubber insulating cap for covering a threaded terminal post, an upper end portion of which is exposed and which has assembled thereon the terminal ends of a plurality of insulated conductors which extend in opposite directions from said post and which are secured on said post by a nut screwed downwardly on the latter against said terminal ends, the combination of: a flat, circular top wall having a hemispherical boss formed integrally therewith and rising upwardly from the upper surface thereof, there being a hole extending axially upwardly through said top wall and into 5 said boss, said hole being of substantially less diameter than said post and being adapted to frictionally receive the latter when said cap is pressed downwardly on said post; and a cylindrical side wall formed integral with and extending downwardly from the periphery of said top wall, said side wall having a plurality of openings extending upwardly from the lower edge thereof for closely receiving said insulated conductors, the frictional engagement of said hole with the threads on said post being substantially relaxed by pinching the upper end of said boss, thereby facilitating the application of said cap to or the removal of said cap from said post.

RANSOM M. FISKE.

References Cited in the file of this patent UNITED STATES PATENTS Number 5 916,435 1,074,907 1,37 6,844

10 Number Name Date Gould Mar. 30, 1909 Spengler Oct. 7, 1913 Weber May 3, 1921 FOREIGN PATENTS Country Date France Apr. 27, 1914 

